Taste plays a central role in clinical medicine and is crucial for pediatric patients because the unpleasant taste of drugs thwarts the benefits of even the most powerful drug. For two reasons, pediatric medications are particularly problematic. First, children often cannot or will not swallow pills or tablets (which encapsulates the inherently bitter tasting medications). Second, their enhanced (relative to adults) sensitivity to bitterness leads them to strongly reject bitter liquid medicines. We propose experimental studies applying recent scientific advances in bitter taste biology which have identified compounds that may interfere with bitter perception by taste receptor cells, to determine: (1) the effectiveness of these bitter blockers in children and adults for different model bitter compounds and (2) how age and genetic variation affects the efficacy of the bitter blockers.